Ink composition for light-emitting device, light-emitting device manufactured using ink composition, and electronic apparatus including light-emitting device

ABSTRACT

An ink composition for a light-emitting device may include: quantum dots; and a mixed solvent of a first solvent, a second solvent, and a third solvent, wherein the first solvent may be a C6-C50 aromatic hydrocarbon, the second solvent may be a C1-C20 aliphatic hydrocarbon, and the third solvent may be a ternary alkyl phosphine and/or a ternary alkyl amine.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2022-0021726, filed on Feb. 18, 2022, in the KoreanIntellectual Property Office, the entire content of which is herebyincorporated by reference.

BACKGROUND 1. Field

One or more aspects of embodiments of the present disclosure relate toan ink composition for a light-emitting device, a light-emitting devicemanufactured utilizing the ink composition, and an electronic apparatusincluding the light-emitting device.

2. Description of the Related Art

Quantum dots are nanocrystals of semiconductor materials and exhibit aquantum confinement effect. When quantum dots receive light from anexcitation source and thus reach an energy excited state, they emitenergy by themselves according to a corresponding energy band gap. Inthis regard, even in the same material (e.g., substantially the samematerial composition), the wavelength may vary depending on the particlesize, and accordingly, by adjusting the size of quantum dots, lighthaving the desired or suitable wavelength range may be obtained, andexcellent or improved color purity and high luminescence efficiency maybe obtained. Thus, quantum dots may be applicable to various devices.

Due to the quantum confinement effect, the particle size of quantum dotsmay be controlled or selected to realize the emission of various colorsand improve luminescence characteristics.

SUMMARY

One or more aspects of embodiments of the present disclosure include anink composition utilized in an emission layer of a light-emitting devicewith improved efficiency.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments of the disclosure.

According to one or more embodiments, an ink composition for alight-emitting device may include quantum dots, and a mixed solvent of afirst solvent, a second solvent, and a third solvent, wherein the firstsolvent may be a C₆-C₅₀ aromatic hydrocarbon, the second solvent may bea C₁-C₂₀ aliphatic hydrocarbon, and the third solvent may be a ternaryalkyl phosphine and/or ternary alkyl amine.

According to one or more embodiments, a light-emitting device mayinclude a first electrode, a second electrode facing the firstelectrode, an interlayer between the first electrode and the secondelectrode and including an emission layer, wherein the emission layer isprepared by utilizing the ink composition of the present embodiments.

According to one or more embodiments, an electronic apparatus mayinclude the light-emitting device.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic view of one or more embodiments a light-emittingdevice according to one or more embodiments;

FIG. 2 is a schematic cross-sectional view of one or more embodiments alight-emitting apparatus according to one or more embodiments; and

FIG. 3 is a schematic cross-sectional view of a light-emitting apparatusaccording to one or more other embodiments.

DETAILED DESCRIPTION

Reference will now be made in more detail to embodiments, examples ofwhich are illustrated in the accompanying drawings, wherein likereference numerals refer to like elements throughout, and duplicativedescriptions thereof may not be provided. In this regard, the presentembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described, by referring to the drawings, toexplain aspects of the present description. As utilized herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. As used herein, expressions such as “at leastone of”, “one of”, and “selected from”, when preceding a list ofelements, modify the entire list of elements and do not modify theindividual elements of the list. For example, throughout the disclosure,the expressions “at least one selected from a, b and c”, “at least oneof a, b or c”, and “at least one of a, b and/or c” indicate only a, onlyb, only c, both (e.g., simultaneously) a and b, both (e.g.,simultaneously) a and c, both (e.g., simultaneously) b and c, all of a,b, and c, or variations thereof. Further, the use of “may” whendescribing embodiments of the present disclosure refers to “one or moreembodiments of the present disclosure”.

As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

It will be further understood that the terms “includes,” “including,”“comprises,” and/or “comprising,” when used in this specification,specify the presence of stated features, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, steps, operations, elements, components, and/orgroups thereof.

As used herein, the terms “use,” “using,” and “used” may be consideredsynonymous with the terms “utilize,” “utilizing,” and “utilized,”respectively. It will be understood that when an element is referred toas being “on,” “connected to,” or “coupled to” another element, it maybe directly on, connected, or coupled to the other element or one ormore intervening elements may also be present. When an element isreferred to as being “directly on,” “directly connected to,” or“directly coupled to” another element, there are no intervening elementspresent.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper,” “bottom,” “top” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below” or “beneath”other elements or features would then be oriented “above” or “over” theother elements or features. Thus, the term “below” may encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations), and the spatiallyrelative descriptors used herein should be interpreted accordingly.

As used herein, the terms “substantially”, “about”, and similar termsare used as terms of approximation and not as terms of degree, and areintended to account for the inherent deviations in measured orcalculated values that would be recognized by those of ordinary skill inthe art. “About” or “approximately,” as used herein, is inclusive of thestated value and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” may mean within one or morestandard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

Any numerical range recited herein is intended to include all sub-rangesof the same numerical precision subsumed within the recited range. Forexample, a range of “1.0 to 10.0” is intended to include all subrangesbetween (and including) the recited minimum value of 1.0 and the recitedmaximum value of 10.0, that is, having a minimum value equal to orgreater than 1.0 and a maximum value equal to or less than 10.0, suchas, for example, 2.4 to 7.6. Any maximum numerical limitation recitedherein is intended to include all lower numerical limitations subsumedtherein and any minimum numerical limitation recited in thisspecification is intended to include all higher numerical limitationssubsumed therein. Accordingly, Applicant reserves the right to amendthis specification, including the claims, to expressly recite anysub-range subsumed within the ranges expressly recited herein.

The electronic device and/or any other relevant devices or componentsaccording to embodiments of the present invention described herein maybe implemented utilizing any suitable hardware, firmware (e.g. anapplication-specific integrated circuit), software, or a combination ofsoftware, firmware, and hardware. For example, the various components ofthe apparatus may be formed on one integrated circuit (IC) chip or onseparate IC chips. Further, the various components of the apparatus maybe implemented on a flexible printed circuit film, a tape carrierpackage (TCP), a printed circuit board (PCB), or formed on onesubstrate. Further, the various components of the apparatus may be aprocess or thread, running on one or more processors, in one or morecomputing devices, executing computer program instructions andinteracting with other system components for performing the variousfunctionalities described herein. The computer program instructions arestored in a memory which may be implemented in a computing device usinga standard memory device, such as, for example, a random access memory(RAM). The computer program instructions may also be stored in othernon-transitory computer readable media such as, for example, a CD-ROM,flash drive, or the like. Also, a person of skill in the art shouldrecognize that the functionality of various computing devices may becombined or integrated into a single computing device, or thefunctionality of a particular computing device may be distributed acrossone or more other computing devices without departing from the scope ofthe exemplary embodiments of the present invention.

Quantum dots synthesized based on a solution process may be dispersed incolloidal form. For example, organic substances with long chains such asoleic acid, myristic acid, and/or stearic acid may be utilized assurfactants utilized in quantum dot synthesis, and may ultimately act asa ligand for passivating quantum dots.

In this case, a mechanism by which colloidal dispersibility ismaintained is steric stabilization, which, because nanoparticleaggregation occurs when the distance between particles is close to acertain extent (e.g., is suitably close), may prevent or reduce the riskof particles approaching each other at a distance where the dispersingforce is strong and may prevent or reduce agglomeration, by adsorbingpolymer materials that may apply steric repulsion to the surfaces ofdispersed particles.

In quantum dots in the related art, long-chain organic ligands mayprovide a steric repulsive force, and thus, a non-polar organic solventmay be utilized as a dispersing solvent.

As a bond between a quantum dot shell and an organic ligand is in adynamic equilibrium state, an unbound organic ligand may contribute toquantum dot stabilization. On the other hand, a wide bandgap of anorganic ligand for quantum dot surface stabilization, e.g., an alkylchain ligand, may act as a barrier to charge injection. When there aremany unbound organic ligands, electric mobility may be disturbed, andproperties may deteriorate.

It may be possible to remove quantum dot forms (e.g. unbound organicligands), off (or from) a light-emitting device, but during thisprocess, a ligand that is bound to a surface may also be removed and maycause a surface defect site, which may act as an electron trap in thelight-emitting device. Thus, there is a problem that devicecharacteristics may be deteriorated.

A quantum dot shell surface may include (e.g., consist of) metal and/orchalcogenide.

A ligand utilized for quantum dot may mainly use a fatty acid type orkind with a long chain, and the ligand of a fatty acid type or kind maybe bound to a metal part of the quantum dot surface.

The portion where a surface defect of the quantum dot may be generatedmay often be a chalcogenide portion of the surface of the quantum dot,and this may cause deterioration of properties.

An ink composition for a light-emitting device may include:

quantum dots; and a mixed solvent of a first solvent, a second solvent,and a third solvent,

wherein the first solvent may be a C₆-C₅₀ aromatic hydrocarbon,

the second solvent may be a C₁-C₂₀ aliphatic hydrocarbon, and

the third solvent may be a ternary alkyl phosphine and/or ternary alkylamine.

The aliphatic hydrocarbon may be, for example, a saturated orunsaturated aliphatic hydrocarbon. For example, the aliphatichydrocarbon may be a branched or linear alkyl compound.

The aromatic hydrocarbon may be, for example, an aryl compound.

In the ternary alkyl phosphine and/or ternary alkyl amine, the alkyl maybe, for example, a C₁-C₂₀ alkyl group. The alkyl may be, for example, aC₆-C₂₀ alkyl group. The ternary alkyl phosphine may be a group in whichthree alkyl groups are bound to P, and the ternary alkyl amine may be agroup in which three alkyl groups are bound to N, wherein the threealkyl groups may be identical to or different from each other.

The third solvent may improve characteristics of a light-emitting deviceby healing (e.g., mending) the defect site of quantum dots.

According to one or more embodiments, a boiling point of the thirdsolvent is more than 220° C. and no more than about 500° C. Consideringa viscosity and a dryness of the ink composition for a light-emittingdevice and a content (e.g., amount) of a third solvent in the inkcomposition, the boiling point may be within the above range.

According to one or more embodiments, the first solvent may includetoluene, xylene, ethyl benzene, diethyl benzene, mesitylene, propylbenzene, cyclohexyl benzene, dimethoxy benzene, anisole, ethoxytoluene,phenoxytoluene, isopropyl biphenyl, dimethyl anisole, propyl anisole,1-ethyl naphthalene, 2-ethyl naphthalene, 2-ethylbiphenyl, octylbenzene, or any combination thereof.

According to one or more embodiments, the second solvent may includen-octane, n-nonane, n-decane, n-undecane, n-dodecane, n-tridecane,n-tetradecane, n-pentadecane, n-hexadecane, 2-methylheptane,3-methylheptane, 4-methylheptane, 2,2-dimethylhexane,2,3-dimethylhexane, 2,4-dimethylhexane, 2,5-dimethylhexane,3,3-dimethylhexane, 3-ethylhexane, 2,2,4-trimethylpentane,2-methyloctane, 2-methylnonane, 2-methyldecane, 2-methylundecane,2-methyldodecane, 2-methyltridecane, or any combination thereof.

According to one or more embodiments, the third solvent may includetripropylphosphine, tributylphosphine, trihexylphosphine,trioctylphosphine, tripropylamine, tributylamine, trihexylamine,triheptylamine, trioctylamine, or any combination thereof.

According to one or more embodiments, the second solvent may be in arange of about 20 percent by volume (vol %) to about 70 vol %, based on100 vol % of the first solvent.

According to one or more embodiments, the third solvent may be in arange of about 1 vol % to about 20 vol %, based on 100 vol % of thefirst solvent.

When a ratio of the first solvent, the second solvent, and the thirdsolvent is within their respective above ranges, an emission layer maybe formed without difficulty (e.g., suitably formed) by performing (orutilizing) the ink composition for a light-emitting device according toone or more embodiments in a solution process.

A quantum dot is a spherical (or substantially spherical) semiconductornanomaterial having a size of several to several hundreds of nm, and mayinclude a core including (e.g., consisting of) a material with a smallband gap and a shell around (e.g., surrounding) the core.

According to one or more embodiments, the quantum dot may have acore-shell structure including a core including a semiconductorcompound; and a shell including a metal oxide, a metalloid oxide, anon-metal oxide, a semiconductor compound, or a combination thereof.

The semiconductor compound, the metal oxide, the metalloid oxide, and/orthe non-metal oxide will be described in more detail herein below.

According to one or more embodiments, a viscosity (at 25 C.) of thecomposition may be in a range of about 2 centipoise (cP) to about 10 cP.

According to one or more embodiments, a surface tension of thecomposition may be in a range of about 20 dyne/cm to about 40 dyne/cm.

According to one or more embodiments, a vapor pressure of thecomposition may be less than 10⁻² mmHg.

When the viscosity, surface tension, and/or vapor pressure are withintheir respective above ranges, there may be no difficulty in forming(e.g., it may be suitably easy to form) a layer utilizing a solutionprocess, e.g., spin coating and/or inkjet process, by utilizing the inkcomposition according to one or more embodiments.

Description of FIG. 1

FIG. 1 is a schematic view of a light-emitting device 10 according toone or more embodiments. The light-emitting device 10 may include afirst electrode 110, an interlayer 130, and a second electrode 150.

Hereinafter, the structure of the light-emitting device 10 according toone or more embodiments and a method of manufacturing the light-emittingdevice 10 according to one or more embodiments will be described inconnection with FIG. 1 .

First Electrode 110

In FIG. 1 , a substrate may be additionally located under the firstelectrode 110 or above the second electrode 150. The substrate may be aglass substrate and/or a plastic substrate. The substrate may be aflexible substrate including plastic having excellent or suitable heatresistance and durability, for example, polyimide, polyethyleneterephthalate (PET), polycarbonate, polyethylene naphthalate,polyarylate (PAR), polyetherimide, or any combination thereof.

The first electrode 110 may be formed by depositing or sputtering, onthe substrate, a material for forming the first electrode 110. When thefirst electrode 110 is an anode, a high work function material that mayeasily or suitably inject holes may be utilized as a material for afirst electrode.

The first electrode 110 may be a reflective electrode, asemi-transmissive electrode, or a transmissive electrode. When the firstelectrode 110 is a transmissive electrode, a material for forming thefirst electrode 110 may be indium tin oxide (ITO), indium zinc oxide(IZO), tin oxide (SnO₂), zinc oxide (ZnO), or any combination thereof.In some embodiments, when the first electrode 110 is a semi-transmissiveelectrode or a reflective electrode, magnesium (Mg), silver (Ag),aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium(Mg—In), magnesium-silver (Mg—Ag), or any combination thereof may beutilized as a material for forming the first electrode 110.

The first electrode 110 may have a single-layered structure including(e.g., consisting of) a single layer or a multi-layered structureincluding two or more layers. In some embodiments, the first electrode110 may have a triple-layered structure of ITO/Ag/ITO.

Interlayer 130

The interlayer 130 may be on the first electrode 110. The interlayer 130may include an emission layer.

The interlayer 130 may further include a hole transport region betweenthe first electrode 110 and the emission layer, and an electrontransport region between the emission layer and the second electrode150.

The interlayer 130 may further include metal-containing compounds suchas organometallic compounds, inorganic materials such as quantum dots,and/or the like, in addition to one or more suitable organic materials.

The interlayer 130 may include: i) at least two emitting unitssequentially stacked between the first electrode 110 and the secondelectrode 150; and ii) a charge generation layer located between the atleast two emitting units. When the interlayer 130 includes the at leasttwo emitting units and a charge generation layer, the light-emittingdevice 10 may be a tandem light-emitting device.

Hole Transport Region in Interlayer 130

The hole transport region may have i) a single-layered structureincluding (e.g., consisting of) a single layer including (e.g.,consisting of) a single material, ii) a single-layered structureincluding (e.g., consisting of) a single layer including a plurality ofdifferent materials, or iii) a multi-layered structure having aplurality of layers including a plurality of different materials.

The hole transport region may include a hole injection layer, a holetransport layer, an emission auxiliary layer, an electron blockinglayer, or a combination thereof.

For example, the hole transport region may have a multi-layeredstructure, e.g., a hole injection layer/hole transport layer structure,a hole injection layer/hole transport layer/emission auxiliary layerstructure, a hole injection layer/emission auxiliary layer structure, ahole transport layer/emission auxiliary layer structure, or a holeinjection layer/hole transport layer/electron blocking layer structure,wherein layers of each structure are sequentially stacked on the firstelectrode 110 in each stated order.

The hole transport region may include the compound represented byFormula 201, the compound represented by Formula 202, or any combinationthereof:

-   -   wherein, in Formulae 201 and 202,    -   L₂₀₁ to L₂₀₄ may each independently be a C₃-C₆₀ carbocyclic        group unsubstituted or substituted with at least one R_(10a) or        a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at        least one R_(10a),    -   L₂₀₅ may be *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a C₁-C₂₀ alkylene        group unsubstituted or substituted with at least one R_(10a), a        C₂-C₂₀ alkenylene group unsubstituted or substituted with at        least one R_(10a), a C₃-C₆₀ carbocyclic group unsubstituted or        substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic        group unsubstituted or substituted with at least one R_(10a),    -   xa1 to xa4 may each independently be an integer from 0 to 5,    -   xa5 may be an integer from 1 to 10,    -   R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be a C₃-C₆₀        carbocyclic group unsubstituted or substituted with at least one        R_(10a) or a C₁-C₆ heterocyclic group unsubstituted or        substituted with at least one R_(10a),    -   R₂₀₁ and R₂₀₂ may optionally be bound to each other via a single        bond, a C₁-C₅ alkylene group unsubstituted or substituted with        at least one R_(10a), or a C₂-C₅ alkenylene group unsubstituted        or substituted with at least one R_(10a) to form a C₈-C₆₀        polycyclic group (e.g., a carbazole group and/or the like)        unsubstituted or substituted with at least one R_(10a) (e.g.,        Compound HT16 described herein),    -   R₂₀₃ and R₂₀₄ may optionally be bound to each other via a single        bond, a C₁-C₅ alkylene group unsubstituted or substituted with        at least one R_(10a), or a C₂-C₅ alkenylene group unsubstituted        or substituted with at least one R_(10a) to form a C₈-C₆₀        polycyclic group unsubstituted or substituted with at least one        R_(10a), and    -   na1 may be an integer from 1 to 4.

In some embodiments, Formulae 201 and 202 may each include at least oneof groups represented by Formulae CY201 to CY217:

-   -   wherein, in Formulae CY201 to CY217, R_(10b) and R_(10c) may        each be understood by referring to the descriptions of R_(10a),        ring CY201 to ring CY204 may each independently be a C₃-C₂₀        carbocyclic group or a C₁-C₂₀ heterocyclic group, and at least        one hydrogen in Formulae CY201 to CY217 may be unsubstituted or        substituted with R_(10a).

In some embodiments, in Formulae CY201 to CY217, ring CY201 to ringCY204 may each independently be a benzene group, a naphthalene group, aphenanthrene group, or an anthracene group.

In one or more embodiments, Formulae 201 and 202 may each include atleast one of groups represented by Formulae CY201 to CY203.

In one or more embodiments, Formula 201 may include at least one ofgroups represented by Formulae CY201 to CY203 and at least one of groupsrepresented by Formulae CY204 to CY217.

In one or more embodiments, in Formula 201, xa1 may be 1, R₂₀₁ may be agroup represented by any one of Formulae CY201 to CY203, xa2 may be 0,and R₂₀₂ may be a group represented by any one of Formulae CY204 toCY207.

In one or more embodiments, Formulae 201 and 202 may each not includegroups represented by Formulae CY201 to CY203.

In one or more embodiments, Formulae 201 and 202 may each not include(may each not include any) groups represented by Formulae CY201 toCY203, and may each include at least one of groups represented byFormulae CY204 to CY217.

In one or more embodiments, Formulae 201 and 202 may each not include(may each not include any) groups represented by Formulae CY201 toCY217.

In some embodiments, the hole transport region may include at least oneof Compounds HT1 to HT46, m-MTDATA, TDATA, 2-TNATA, NPB (NPD), β-NPB,TPD, spiro-TPD, spiro-NPB, methylated-NPB, TAPC, HMTPD,4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphorsulfonic acid (PANI/CSA),polyaniline/poly(4-styrenesulfonate (PANI/PSS), or any combinationthereof:

The thickness of the hole transport region may be in a range of about 50Angstroms (Å) to about 10,000 Å, and in some embodiments, about 100 Å toabout 4,000 Å. When the hole transport region includes a hole injectionlayer, a hole transport layer, or any combination thereof, the thicknessof the hole injection layer may be in a range of about 100 Å to about9,000 Å, and in some embodiments, about 100 Å to about 1,000 Å, and thethickness of the hole transport layer may be in a range of about 50 Å toabout 2,000 Å, and in some embodiments, about 100 Å to about 1,500 Å.When the thicknesses of the hole transport region, the hole injectionlayer, and the hole transport layer are within any of their respectiveranges, excellent or improved hole transport characteristics may beobtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase light emission efficiency bycompensating for an optical resonance distance according to thewavelength of light emitted by an emission layer. The electron blockinglayer may prevent or reduce leakage of electrons to a hole transportregion from the emission layer. Materials that may be included in thehole transport region may also be included in an emission auxiliarylayer and/or an electron blocking layer.

p-Dopant

The hole transport region may include a charge generating material aswell as the aforementioned materials to improve conductive properties ofthe hole transport region. The charge generating material may besubstantially homogeneously or non-homogeneously dispersed (for example,as a single layer including (e.g., consisting of) charge generatingmaterial) in the hole transport region.

The charge generating material may include, for example, a p-dopant.

In some embodiments, a lowest unoccupied molecular orbital (LUMO) energylevel of the p-dopant may be −3.5 eV or less.

In some embodiments, the p-dopant may include a quinone derivative, acompound containing a cyano group, a compound containing element EL1 andelement EL2, or any combination thereof.

Examples of the quinone derivative may include TCNQ, F4-TCNQ, and thelike.

Examples of the compound containing a cyano group may include HAT-CN, acompound represented by Formula 221, and the like:

wherein, in Formula 221,

R₂₂₁ to R₂₂₃ may each independently be a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a), and

at least one of R₂₂₁ to R₂₂₃ may each independently be: a C₃-C₆₀carbocyclic group or a C₁-C₆₀ heterocyclic group, substituted with acyano group; —F; —Cl; —Br; —I; a C₁-C₂₀ alkyl group substituted with acyano group, —F, —Cl, —Br, —I, or any combination thereof; or anycombination thereof.

In the compound containing element EL1 and element EL2, element EL1 maybe a metal, a metalloid, or a combination thereof, and element EL2 maybe non-metal, a metalloid, or a combination thereof.

Examples of the metal may include: an alkali metal (e.g., lithium (Li),sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and/or thelike); an alkaline earth metal (e.g., beryllium (Be), magnesium (Mg),calcium (Ca), strontium (Sr), barium (Ba), and/or the like); atransition metal (e.g., titanium (Ti), zirconium (Zr), hafnium (Hf),vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum(Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron(Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium(Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver(Ag), gold (Au), and/or the like); post-transition metal (e.g., zinc(Zn), indium (In), tin (Sn), and/or the like); a lanthanide metal (e.g.,lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd),promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium(Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm),ytterbium (Yb), lutetium (Lu), and/or the like); and the like.

Examples of the metalloid may include silicon (Si), antimony (Sb),tellurium (Te), and the like.

Examples of the non-metal may include oxygen (O), halogen (e.g., F, Cl,Br, I, and/or the like), and the like.

For example, the compound containing element EL1 and element EL2 mayinclude a metal oxide, a metal halide (e.g., metal fluoride, metalchloride, metal bromide, metal iodide, and/or the like), a metalloidhalide (e.g., a metalloid fluoride, a metalloid chloride, a metalloidbromide, a metalloid iodide, and/or the like), a metal telluride, or anycombination thereof.

Examples of the metal oxide may include tungsten oxide (e.g., WO, W₂O₃,WO₂, WO₃, W₂O₅, and/or the like), vanadium oxide (e.g., VO, V₂O₃, VO₂,V₂O₅, and/or the like), molybdenum oxide (MoO, Mo₂O₃, MoO₂, MoO₃, Mo₂O₅,and/or the like), rhenium oxide (e.g., ReO₃ and/or the like), and thelike.

Examples of the metal halide may include alkali metal halide, alkalineearth metal halide, transition metal halide, post-transition metalhalide, lanthanide metal halide, and the like.

Examples of the alkali metal halide may include LiF, NaF, KF, RbF, CsF,LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI,RbI, CsI, and the like.

Examples of the alkaline earth metal halide may include BeF₂, MgF₂,CaF₂, SrF₂, BaF₂, BeCl₂, MgCl₂, CaCl₂), SrCl₂, BaCl₂, BeBr₂, MgBr₂,CaBr₂, SrBr₂, BaBr₂, BeI₂, MgI₂, Cal₂, SrI₂, BaI₂, and the like.

Examples of the transition metal halide may include titanium halide(e.g., TiF₄, TiCl₄, TiBr₄, TiI₄, and/or the like), zirconium halide(e.g., ZrF₄, ZrCl₄, ZrBr₄, ZrI₄, and/or the like), hafnium halide (e.g.,HfF₄, HfCl₄, HfBr₄, HfI₄, and/or the like), vanadium halide (e.g., VF₃,VCl₃, VBr₃, VI₃, and/or the like), niobium halide (e.g., NbF₃, NbCl₃,NbBr₃, NbI₃, and/or the like), tantalum halide (e.g., TaF₃, TaCl₃,TaBr₃, TaI₃, and/or the like), chromium halide (e.g., CrF₃, CrCl₃,CrBr₃, CrI₃, and/or the like), molybdenum halide (e.g., MoF₃, MoCl₃,MoBr₃, MoI₃, and/or the like), tungsten halide (e.g., WF₃, WCl₃, WBr₃,WI₃, and/or the like), manganese halide (e.g., MnF₂, MnCl₂, MnBr₂, MnI₂,and/or the like), technetium halide (e.g., TcF₂, TcCl₂, TcBr₂, TcI₂,and/or the like), rhenium halide (e.g., ReF₂, ReCl₂, ReBr₂, ReI₂, and/orthe like), iron halide (e.g., FeF₂, FeCl₂, FeBr₂, FeI₂, and/or thelike), ruthenium halide (e.g., RuF₂, RuCl₂, RuBr₂, RuI₂, and/or thelike), osmium halide (e.g., OsF₂, OsCl₂, OsBr₂, OsI₂, and/or the like),cobalt halide (e.g., CoF₂, CoCl₂, CoBr₂, CoI₂, and/or the like), rhodiumhalide (e.g., RhF₂, RhCl₂, RhBr₂, Rhl₂, and/or the like), iridium halide(e.g., IrF₂, IrCl₂, IrBr₂, IrI₂, and/or the like), nickel halide (e.g.,NiF₂, NiCl₂, NiBr₂, NiI₂, and/or the like), palladium halide (e.g.,PdF₂, PdCl₂, PdBr₂, PdI₂, and/or the like), platinum halide (e.g., PtF₂,PtCl₂, PtBr₂, PtI₂, and/or the like), copper halide (e.g., CuF, CuCl,CuBr, CuI, and/or the like), silver halide (e.g., AgF, AgCl, AgBr, AgI,and/or the like), gold halide (e.g., AuF, AuCl, AuBr, AuI, and/or thelike), and the like.

Examples of the post-transition metal halide may include zinc halide(e.g., ZnF₂, ZnCl₂, ZnBr₂, ZnI₂, and/or the like), indium halide (e.g.,InI₃ and/or the like), tin halide (e.g., SnI₂ and/or the like), and thelike.

Examples of the lanthanide metal halide may include YbF, YbF₂, YbF₃,SmF₃, YbCl, YbCl₂, YbCl₃, SmCl₃, YbBr, YbBr₂, YbBr₃, SmBr₃, YbI, YbI₂,YbI₃, SmI₃, and the like.

Examples of the metalloid halide may include antimony halide (e.g.,SbCl₅ and/or the like) and the like.

Examples of the metal telluride may include alkali metal telluride(e.g., Li₂Te, Na₂Te, K₂Te, Rb₂Te, Cs₂Te, and/or the like), alkalineearth metal telluride (e.g., BeTe, MgTe, CaTe, SrTe, BaTe, and/or thelike), transition metal telluride (e.g., TiTe₂, ZrTe₂, HfTe₂, V₂Te₃,Nb₂Te₃, Ta₂Te₃, Cr₂Te₃, Mo₂Te₃, W₂Te₃, MnTe, TcTe, ReTe, FeTe, RuTe,OsTe, CoTe, RhTe, IrTe, NiTe, PdTe, PtTe, Cu₂Te, CuTe, Ag₂Te, AgTe,Au₂Te, and/or the like), post-transition metal telluride (e.g., ZnTeand/or the like), lanthanide metal telluride (e.g., LaTe, CeTe, PrTe,NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, and/orthe like), and the like.

Emission Layer in Interlayer 130

When the light-emitting device 10 is a full color light-emitting device,the emission layer may be patterned into a red emission layer, a greenemission layer, and/or a blue emission layer, according to a sub-pixel.In one or more embodiments, the emission layer may have a stackedstructure. The stacked structure may include two or more layers selectedfrom a red emission layer, a green emission layer, and a blue emissionlayer. The two or more layers may be in direct contact with each other.In some embodiments, the two or more layers may be separated from eachother. In one or more embodiments, the emission layer may include two ormore materials. The two or more materials may include a redlight-emitting material, a green light-emitting material, or a bluelight-emitting material. The two or more materials may be mixed witheach other in a single layer. The two or more materials mixed with eachother in the single layer may emit white light.

The emission layer may include the quantum dots.

The thickness of the emission layer may be in a range of about 100 Å toabout 1,000 Å, and in some embodiments, about 200 Å to about 600 Å. Whenthe thickness of the emission layer is within any of these ranges,improved luminescence characteristics may be obtained without asubstantial increase in driving voltage.

Quantum Dots

The emission layer may include quantum dots.

The term “quantum dot” as utilized herein refers to a crystal of asemiconductor compound and may include any suitable material capable ofemitting emission wavelengths of one or more suitable lengths accordingto the size of the crystal. The diameter of the quantum dot may be, forexample, in a range of about 1 nm to about 10 nm. Here, the diameter mayrefer to an average quantum dot particle size, for example, a mediandiameter (D50) measured utilizing a laser diffraction particle diameterdistribution meter.

Quantum dots may be synthesized by a wet chemical process, an organicmetal chemical vapor deposition process, a molecular beam epitaxyprocess, or any similar process.

The wet chemical process is a method of growing a quantum dot particlecrystal by mixing a precursor material with an organic solvent. When thecrystal grows, the organic solvent may naturally serve as a dispersantcoordinated on the surface of the quantum dot crystal and control thegrowth of the crystal. Thus, the wet chemical method may be easier(e.g., more suitable) to perform than the vapor deposition process sucha metal organic chemical vapor deposition (MOCVD) or a molecular beamepitaxy (MBE) process. Further, the growth of quantum dot particles maybe controlled or selected with a lower manufacturing cost.

The quantum dot may include a group II-VI semiconductor compound; agroup III-V semiconductor compound; a group III-VI semiconductorcompound; a group 1-III-VI semiconductor compound; a group IV-VIsemiconductor compound; a group IV element, a group IV compound; or anycombination thereof.

Examples of the group II-VI semiconductor compound may include a binarycompound such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe,MgSe, and/or MgS; a ternary compound such as CdSeS, CdSeTe, CdSTe,ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe,CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, and/or MgZnS; aquaternary compound such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS,CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and/or HgZnSTe; and anycombination thereof.

Examples of the group III-V semiconductor compound may include a binarycompound such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP,InAs, and/or InSb; a ternary compound such as GaNP, GaNAs, GaNSb, GaPAs,GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs,InNSb, InPAs, and/or InPSb; a quaternary compound such as GaAlNP,GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs,GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and/or InAlPSb; and anycombination thereof. In some embodiments, the group III-V semiconductorcompound may further include a group II element. Examples of the groupIII-V semiconductor compound further including the group II element mayinclude InZnP, InGaZnP, InAlZnP, and the like.

Examples of the III-VI group semiconductor compound may include a binarycompound such as GaS, GaSe, Ga₂Se₃, GaTe, InS, InSe, In₂S₃, In₂Se₃,InTe, and/or the like; a ternary compound such as InGaS₃, InGaSe₃,and/or the like; and any combination thereof.

Examples of the group I-III-VI semiconductor compound may include aternary compound such as AgInS, AgInS₂, CuInS, CuInS₂, CuGaO₂, AgGaO₂,AgAlO₂, or any combination thereof.

Examples of the group IV-VI semiconductor compound may include a binarycompound such as SnS, SnSe, SnTe, PbS, PbSe, and/or PbTe; a ternarycompound such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS,SnPbSe, and/or SnPbTe; a quaternary compound such as SnPbSSe, SnPbSeTe,and/or SnPbSTe; and any combination thereof.

Examples of the group IV element and the group IV compound may be asingle element material such as Si and/or Ge; a binary compound such asSiC and/or SiGe; and any combination thereof.

Individual elements included in the multi-element compound, such as abinary compound, a ternary compound, and/or a quaternary compound, maybe present in a particle thereof at a substantially uniform ornon-substantially uniform concentration.

The quantum dot may have a single structure in which the concentrationof each element included in the quantum dot is substantially uniform ora core-shell double structure. In some embodiments, materials includedin the core may be different from materials included in the shell.

The shell of the quantum dot may serve as a protective layer forpreventing or reducing chemical denaturation of the core to maintainsemiconductor characteristics and/or as a charging layer for impartingelectrophoretic characteristics to the quantum dot. The shell may be amonolayer or a multilayer. An interface between a core and a shell mayhave a concentration gradient where a concentration of elements presentin the shell decreases toward the core.

Examples of the shell of the quantum dot include a metal oxide, ametalloid oxide, a nonmetal oxide, a semiconductor compound, andcombinations thereof. Examples of the metal oxide, the metalloid oxide,and the nonmetal oxide may include: a binary compound such as SiO₂,Al₂O₃, TiO₂, ZnO, MnO, Mn₂O₃, Mn₃O₄, CuO, FeO, Fe₂O₃, Fe₃O₄, CoO, Co₃O₄,and/or NiO; a ternary compound such as MgAl₂O₄, CoFe₂O₄, NiFe₂O₄, and/orCoMn₂O₄; and any combination thereof. Examples of the semiconductorcompound may include a group II-VI semiconductor compound; a group III-Vsemiconductor compound; a group III-VI semiconductor compound; a groupI-III-VI semiconductor compound; a group IV-VI semiconductor compound;and any combination thereof. In some embodiments, the semiconductorcompound may be CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs,GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, orany combination thereof.

The quantum dot may have a full width of half maximum (FWHM) of aspectrum of an emission wavelength of about 45 nm or less, about 40 nmor less, or about 30 nm or less. When the FWHM of the quantum dot iswithin any of these ranges, color purity or color reproducibility may beimproved. In some embodiments, because light emitted through the quantumdots is emitted in all directions, an optical viewing angle may beimproved.

In some embodiments, the quantum dot may be a spherical, pyramidal,multi-arm, and/or cubic nanoparticle, nanotube, nanowire, nanofiber,and/or nanoplate particle.

By adjusting the size of the quantum dot, the energy band gap may alsobe adjusted, thereby obtaining light of one or more suitable wavelengthsin the quantum dot emission layer. By utilizing quantum dots of one ormore suitable sizes, a light-emitting device that may emit light of oneor more suitable wavelengths may be realized. In some embodiments, thesize of the quantum dot may be selected such that the quantum dot mayemit red, green, and/or blue light. In some embodiments, the size of thequantum dot may be selected such that the quantum dot may emit whitelight by combining various light colors.

Electron Transport Region in Interlayer 130

The electron transport region may have i) a single-layered structureincluding (e.g., consisting of) a single layer including (e.g.,consisting of) a single material, ii) a single-layered structureincluding (e.g., consisting of) a single layer including a plurality ofdifferent materials, or iii) a multi-layered structure having aplurality of layers including a plurality of different materials.

The electron transport region may include a hole blocking layer, anelectron transport layer, an electron injection layer, or a combinationthereof.

In some embodiments, the electron transport region may have an electrontransport layer/electron injection layer structure or a hole blockinglayer/electron transport layer/electron injection layer structure,wherein layers of each structure are sequentially stacked over theemission layer in the stated order.

The electron transport region (e.g., a hole blocking layer and/or anelectron transport layer in the electron transport region) may include ametal-free compound including at least one π electron-deficientnitrogen-containing C₁-C₆₀ cyclic group.

In some embodiments, the electron transport region may include acompound represented by Formula 601:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21),  Formula 601

wherein, in Formula 601,

Ar₆₀₁ and L₆₀₁ may each independently be a C₃-C₆₀ carbocyclic groupunsubstituted or substituted with at least one R_(10a) or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least oneR_(10a),

xe11 may be 1, 2, or 3,

xe1 may be 0, 1, 2, 3, 4, or 5,

R₆₀₁ may be a C₃-C₆₀ carbocyclic group unsubstituted or substituted withat least one R_(10a), a C₁-C₆₀ heterocyclic group unsubstituted orsubstituted with at least one R_(10a), —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃),—C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), or —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆₀₃ may each be understood by referring to the description ofQ₁ provided herein,

xe21 may be 1, 2, 3, 4, or 5, and

at least one of Ar₆₀₁, L₆₀₁, and R₆₀₁ may independently be a πelectron-deficient nitrogen-containing C₁-C₆₀ cyclic group unsubstitutedor substituted with at least one R_(10a).

In some embodiments, when xe11 in Formula 601 is 2 or greater, at leasttwo Ar₆₀₁(s) may be bound via a single bond.

In some embodiments, in Formula 601, Ar₆₀₁ may be a substituted orunsubstituted anthracene group.

In some embodiments, the electron transport region may include acompound represented by Formula 601-1:

wherein, in Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N orC(R₆₁₆), and at least one of X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may each be understood by referring to the description ofL₆₀₁ provided herein,

xe611 to xe613 may each be understood by referring to the description ofxe1 provided herein,

R₆₁₁ to R₆₁₃ may each be understood by referring to the description ofR₆₀₁ provided herein, and

R₆₁₄ to R₆₁₆ may each independently be hydrogen, deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a C₃-C₆₀ carbocyclic group unsubstitutedor substituted with at least one R_(10a), or a C₁-C₆₀ heterocyclic groupunsubstituted or substituted with at least one R_(10a).

For example, in Formulae 601 and 601-1, xe1 and xe611 to xe613 may eachindependently be 0, 1, or 2.

The electron transport region may include at least one of Compounds ET1to ET45, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP),4,7-diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq, TAZ, NTAZ, or anycombination thereof:

The thickness of the electron transport region may be in a range ofabout 100 Angstroms (Å) to about 5,000 Å, for example, about 160 Å toabout 4,000 Å. When the electron transport region includes a holeblocking layer, an electron transport layer, or any combination thereof,the thicknesses of the hole blocking layer may be in a range of about 20Å to about 1,000 Å, for example, about 30 Å to about 300 Å, and thethickness of the electron transport layer may be in a range of about 100Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When thethickness of the hole blocking layer and/or the electron transport layeris within any of these ranges, excellent or improved electron transportcharacteristics may be obtained without a substantial increase indriving voltage.

The electron transport region (for example, the electron transport layerin the electron transport region) may further include, in addition tothe materials described above, a metal-containing material.

The metal-containing material may include an alkali metal complex, analkaline earth metal complex, or any combination thereof. A metal ion ofthe alkali metal complex may be a lithium (Li) ion, a sodium (Na) ion, apotassium (K) ion, a rubidium (Rb) ion, and/or a cesium (Cs) ion. Ametal ion of the alkaline earth metal complex may be a beryllium (Be)ion, a magnesium (Mg) ion, a calcium (Ca) ion, a strontium (Sr) ion,and/or a barium (Ba) ion. A ligand coordinated with the metal ion of thealkali metal complex and the alkaline earth metal complex may eachindependently be hydroxyquinoline, hydroxyisoquinoline,hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine,hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxyphenyloxadiazole,hydroxyphenylthiadiazole, hydroxyphenylpyridine,hydroxyphenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine,phenanthroline, cyclopentadiene, or any combination thereof.

For example, the metal-containing material may include a Li complex. TheLi complex may include, e.g., Compound ET-D1 (LiQ) and/or CompoundET-D2:

The electron transport region may include an electron injection layerthat facilitates injection of electrons from the second electrode 150.The electron injection layer may be in direct contact with the secondelectrode 150.

The electron injection layer may have i) a single-layered structureincluding (e.g., consisting of) a single layer including (e.g.,consisting of) a single material, ii) a single-layered structureincluding (e.g., consisting of) a single layer including a plurality ofdifferent materials, or iii) a multi-layered structure having aplurality of layers including a plurality of different materials.

The electron injection layer may include an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal-containing compound, analkaline earth metal-containing compound, a rare earth metal-containingcompound, an alkali metal complex, an alkaline earth metal complex, arare earth metal complex, or any combination thereof.

The alkali metal may be Li, Na, K, Rb, Cs or any combination thereof.The alkaline earth metal may be Mg, Ca, Sr, Ba, or any combinationthereof. The rare earth metal may be Sc, Y, Ce, Tb, Yb, Gd, or anycombination thereof.

The alkali metal-containing compound, the alkaline earthmetal-containing compound, and the rare earth metal-containing compoundmay respectively be an oxide, a halide (e.g., fluoride, chloride,bromide, and/or iodide), a telluride, or any combination thereof of thealkali metal, the alkaline earth metal, and the rare earth metal,respectively.

The alkali metal-containing compound may be an alkali metal oxide suchas Li₂O, Cs₂O, and/or K₂O; an alkali metal halide such as LiF, NaF, CsF,KF, Lil, NaI, CsI, and/or KI; or any combination thereof. The alkalineearth-metal-containing compound may include an alkaline earth-metaloxide, such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (wherein x is a realnumber satisfying 0<x<1), and/or Ba_(x)Ca_(1-x)O (wherein x is a realnumber satisfying 0<x<1). The rare earth metal-containing compound mayinclude YbF₃, ScF₃, Sc₂O₃, Y₂O₃, Ce₂O₃, GdF₃, TbF₃, YbI₃, ScI3, TbI₃, orany combination thereof. In some embodiments, the rare earthmetal-containing compound may include a lanthanide metal telluride.Examples of the lanthanide metal telluride may include LaTe, CeTe, PrTe,NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe,La₂Te₃, Ce₂Te₃, Pr₂Te₃, Nd₂Te₃, Pm₂Te₃, Sm₂Te₃, Eu₂Te₃, Gd₂Te₃, Tb₂Te₃,Dy₂Te₃, Ho₂Te₃, Er₂Te₃, Tm₂Te₃, Yb₂Te₃, Lu₂Te₃, and the like.

The alkali metal complex, the alkaline earth metal complex, and the rareearth metal complex may each independently include: i) one of ions ofthe alkali metal, alkaline earth metal, and rare earth metal describedabove and ii) a ligand bonded to the metal ion, e.g., hydroxyquinoline,hydroxyisoquinoline, hydroxybenzoquinoline, hydroxyacridine,hydroxyphenanthridine, hydroxyphenyloxazole, hydroxyphenylthiazole,hydroxyphenyloxadiazole, hydroxyphenylthiadiazole,hydroxyphenylpyridine, hydroxyphenylbenzimidazole,hydroxyphenylbenzothiazole, bipyridine, phenanthroline, cyclopentadiene,or any combination thereof.

The electron injection layer may include (e.g., consist of) an alkalimetal, an alkaline earth metal, a rare earth metal, an alkalimetal-containing compound, an alkaline earth metal-containing compound,a rare earth metal-containing compound, an alkali metal complex, analkaline earth metal complex, a rare earth metal complex, or anycombination thereof, as described above. In some embodiments, theelectron injection layer may further include an organic material (e.g.,a compound represented by Formula 601).

In some embodiments, the electron injection layer may include (e.g.,consist of) i) an alkali metal-containing compound (e.g., alkali metalhalide), or ii) a) an alkali metal-containing compound (e.g., alkalimetal halide); and b) an alkali metal, an alkaline earth metal, a rareearth metal, or any combination thereof. In some embodiments, theelectron injection layer may be a KI:Yb co-deposition layer, a RbI:Ybco-deposition layer, and/or the like.

When the electron injection layer further includes an organic material,the alkali metal, the alkaline earth metal, the rare earth metal, thealkali metal-containing compound, the alkaline earth metal-containingcompound, the rare earth metal-containing compound, the alkali metalcomplex, the alkaline earth metal complex, the rare earth metal complex,or any combination thereof may be homogeneously or non-homogeneouslydispersed in a matrix including the organic material.

The thickness of the electron injection layer may be in a range of about1 Å to about 100 Å, and in some embodiments, about 3 Å to about 90 Å.When the thickness of the electron injection layer is within any ofthese ranges, excellent or improved electron injection characteristicsmay be obtained without a substantial increase in driving voltage.

Second Electrode 150

The second electrode 150 may be on the interlayer 130. In one or moreembodiments, the second electrode 150 may be a cathode that is anelectron injection electrode. In this embodiment, a material for formingthe second electrode 150 may be a material having a low work function,for example, a metal, an alloy, an electrically conductive compound, orany combination thereof.

The second electrode 150 may include lithium (Li), silver (Ag),magnesium (Mg), aluminum (AI), aluminum-lithium (Al—Li), calcium (Ca),magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ytterbium (Yb),silver-ytterbium (Ag—Yb), ITO, IZO, or any combination thereof. Thesecond electrode 150 may be a transmissive electrode, asemi-transmissive electrode, or a reflective electrode.

The second electrode 150 may have a single-layered structure, or amulti-layered structure including two or more layers.

Capping Layer

A first capping layer may be located outside the first electrode 110,and/or a second capping layer may be located outside the secondelectrode 150. In some embodiments, the light-emitting device 10 mayhave a structure in which the first capping layer, the first electrode110, the interlayer 130, and the second electrode 150 are sequentiallystacked in this stated order, a structure in which the first electrode110, the interlayer 130, the second electrode 150, and the secondcapping layer are sequentially stacked in this stated order, or astructure in which the first capping layer, the first electrode 110, theinterlayer 130, the second electrode 150, and the second capping layerare sequentially stacked in this stated order.

In the light-emitting device 10, light emitted from the emission layerin the interlayer 130 may pass through the first electrode 110 (whichmay be a semi-transmissive electrode or a transmissive electrode) andthrough the first capping layer to the outside. In the light-emittingdevice 10, light emitted from the emission layer in the interlayer 130may pass through the second electrode 150 (which may be asemi-transmissive electrode or a transmissive electrode) and through thesecond capping layer to the outside.

The first capping layer and the second capping layer may improve theexternal luminescence efficiency based on the principle of constructiveinterference. Accordingly, the optical extraction efficiency of thelight-emitting device 10 may be increased, thus improving theluminescence efficiency of the light-emitting device 10.

The first capping layer and the second capping layer may each include amaterial having a refractive index of 1.6 or higher (at 589 nm).

The first capping layer and the second capping layer may eachindependently be a capping layer including an organic material, aninorganic capping layer including an inorganic material, or anorganic-inorganic composite capping layer including an organic materialand an inorganic material.

The first capping layer and the second capping layer may eachindependently include carbocyclic compounds, heterocyclic compounds,amine group-containing compounds, porphine derivatives, phthalocyaninederivatives, naphthalocyanine derivatives, alkali metal complexes,alkaline earth metal complexes, or any combination thereof. Thecarbocyclic compound, the heterocyclic compound, and the aminegroup-containing compound may optionally be substituted with asubstituent of O, N, S, Se, Si, F, Cl, Br, I, or any combinationthereof. In one embodiment, the first capping layer and the secondcapping layer may each independently include an amine-based compound.

In some embodiments, the first capping layer and the second cappinglayer may each independently include the compound represented by Formula201, the compound represented by Formula 202, or any combinationthereof.

In one or more embodiments, the first capping layer and the secondcapping layer may each independently include at least one of CompoundsHT28 to HT33, at least one of Compounds CP1 to CP6, β-NPB, or anycombination thereof:

Electronic Apparatus

The light-emitting device may be included in one or more suitableelectronic apparatuses. In some embodiments, an electronic apparatusincluding the light-emitting device may be a light-emitting apparatusand/or an authentication apparatus.

The electronic apparatus (e.g., a light-emitting apparatus) may furtherinclude, in addition to the light-emitting device, i) a color filter,ii) a color-conversion layer, or iii) a color filter and acolor-conversion layer. The color filter and/or the color-conversionlayer may be provided in at least one traveling direction of lightemitted from the light-emitting device. For example, light emitted fromthe light-emitting device may be blue light or white light. Thelight-emitting device may be understood by referring to the descriptionsprovided herein.

The electronic apparatus may include a first substrate. The firstsubstrate may include a plurality of sub-pixel areas, the color filtermay include a plurality of color filter areas respectively correspondingto the plurality of sub-pixel areas, and the color-conversion layer mayinclude a plurality of color-conversion areas respectively correspondingto the plurality of sub-pixel areas.

A pixel-defining film may be located between the plurality of sub-pixelareas to define each sub-pixel area.

The color filter may further include a plurality of color filter areasand light-blocking patterns between the plurality of color filter areas,and the color-conversion layer may further include a plurality ofcolor-conversion areas and light-blocking patterns between the pluralityof color-conversion areas.

The plurality of color filter areas (or a plurality of color-conversionareas) may include: a first area emitting (e.g., configured to emit)first color light; a second area emitting (e.g., configured to emit)second color light; and/or a third area emitting (e.g., configured toemit) third color light, and the first color light, the second colorlight, and/or the third color light may have different maximum emissionwavelengths. In some embodiments, the first color light may be redlight, the second color light may be green light, and the third colorlight may be blue light. In some embodiments, the plurality of colorfilter areas (or the plurality of color-conversion areas) may includequantum dots. In some embodiments, the first area may include redquantum dots, the second area may include green quantum dots, and thethird area may not include (e.g., may exclude) a quantum dot. Thequantum dot may be understood by referring to the description of thequantum dot provided herein. The first area, the second area, and/or thethird area may each further include an emitter.

In some embodiments, the light-emitting device may be to emit firstlight, the first area may be to absorb the first light to emit 1-1 colorlight, the second area may be to absorb the first light to emit 2-1color light, and the third area may be to absorb the first light to emit3-1 color light. In this embodiment, the 1-1 color light, the 2-1 colorlight, and the 3-1 color light may each have a different maximumemission wavelength. In some embodiments, the first light may be bluelight, the 1-1 color light may be red light, the 2-1 color light may begreen light, and the 3-1 light may be blue light.

The electronic apparatus may further include a thin-film transistor, inaddition to the light-emitting device. The thin-film transistor mayinclude a source electrode, a drain electrode, and an active layer,wherein one of the source electrode or the drain electrode may beelectrically connected to one of the first electrode or the secondelectrode of the light-emitting device.

The thin-film transistor may further include a gate electrode, a gateinsulating film, and/or the like.

The active layer may include a crystalline silicon, an amorphoussilicon, an organic semiconductor, and/or an oxide semiconductor.

The electronic apparatus may further include an encapsulation unit forsealing the light-emitting device. The encapsulation unit may be locatedbetween the light-emitting device and the color filter and/or thecolor-conversion layer. The encapsulation unit may allow light to passto the outside from the light-emitting device and prevent or reducepermeation of the air and/or moisture into the light-emitting device atthe same time (or concurrently). The encapsulation unit may be a sealingsubstrate including transparent glass and/or a plastic substrate. Theencapsulation unit may be a thin-film encapsulating layer including atleast one of an organic layer or an inorganic layer. When theencapsulation unit is a thin-film encapsulating layer, the electronicapparatus may be flexible.

In addition to the color filter and/or the color-conversion layer, oneor more suitable functional layers may be provided on the encapsulationunit depending on the desired use of an electronic apparatus. Examplesof the functional layer may include a touch screen layer, a polarizinglayer, and/or the like. The touch screen layer may be a resistive touchscreen layer, a capacitive touch screen layer, and/or an infrared beamtouch screen layer. The authentication apparatus may be, for example, abiometric authentication apparatus that identifies an individualaccording to biometric information (e.g., a fingertip, a pupil, and/orthe like).

The authentication apparatus may further include a biometric informationcollecting unit, in addition to the light-emitting device describedabove.

The electronic apparatus may be applicable to one or more suitabledisplays, an optical source, lighting, a personal computer (e.g., amobile personal computer), a cellphone, a digital camera, an electronicnote, an electronic dictionary, an electronic game console, a medicaldevice (e.g., an electronic thermometer, a blood pressure meter, aglucometer, a pulse measuring device, a pulse wave measuring device, anelectrocardiograph recorder, an ultrasonic diagnosis device, and/or anendoscope display device), a fish finder, one or more suitablemeasurement devices, gauges (e.g., gauges of an automobile, an airplane,and/or a ship), and/or a projector.

Descriptions of FIGS. 2 and 3

FIG. 2 is a schematic cross-sectional view of an electronic apparatus180 according to one or more embodiments.

The electronic apparatus 180 in FIG. 2 may include a substrate 100, athin-film transistor, a light-emitting device, and an encapsulation unit300 sealing the light-emitting device.

The substrate 100 may be a flexible substrate, a glass substrate, and/ora metal substrate. A buffer layer 210 may be on the substrate 100. Thebuffer layer 210 may prevent or reduce penetration of impurities throughthe substrate 100 and may provide a flat (or substantially flat) surfaceon the substrate 100.

A thin-film transistor may be on the buffer layer 210. The thin-filmtransistor may include an active layer 220, a gate electrode 240, asource electrode 260, and a drain electrode 270.

The active layer 220 may include an inorganic semiconductor such assilicon and/or polysilicon, an organic semiconductor, and/or an oxidesemiconductor and may include a source area, a drain area, and a channelarea.

A gate insulating film 230 for insulating the active layer 220 and thegate electrode 240 may be on the active layer 220, and the gateelectrode 240 may be on the gate insulating film 230.

An interlayer insulating film 250 may be on the gate electrode 240. Theinterlayer insulating film 250 may be between the gate electrode 240 andthe source electrode 260, and between the gate electrode 240 and thedrain electrode 270, to provide insulation therebetween.

The source electrode 260 and the drain electrode 270 may be on theinterlayer insulating film 250. The interlayer insulating film 250 andthe gate insulating film 230 may be formed to expose the source area andthe drain area of the active layer 220, and the source electrode 260 andthe drain electrode 270 may be adjacent to the exposed source area andthe exposed drain area of the active layer 220.

The thin-film transistor may be electrically connected to alight-emitting device to drive the light-emitting device and may beprotected by a passivation layer 280. The passivation layer 280 mayinclude an inorganic insulating film, an organic insulating film, or acombination thereof. A light-emitting device may be on the passivationlayer 280. The light-emitting device may include a first electrode 110,an interlayer 130, and a second electrode 150.

The first electrode 110 may be on the passivation layer 280. Thepassivation layer 280 may not fully cover the drain electrode 270 andmay expose a set or specific area of the drain electrode 270, and thefirst electrode 110 may be connected to the exposed area of the drainelectrode 270.

A pixel-defining film 290 may be on the first electrode 110. Thepixel-defining film 290 may expose a specific area of the firstelectrode 110, and the interlayer 130 may be formed in the exposed areaof the first electrode 110. The pixel-defining film 290 may be apolyimide and/or polyacryl organic film. In one or more embodiments,some higher layers of the interlayer 130 may extend to the upper portionof the pixel-defining film 290 and may be provided in the form of acommon layer.

The second electrode 150 may be on the interlayer 130, and a cappinglayer 170 may be additionally formed on the second electrode 150. Thecapping layer 170 may be formed to cover the second electrode 150.

The encapsulation unit 300 may be on the capping layer 170. Theencapsulation unit 300 may be on the light-emitting device to protect alight-emitting device from moisture and/or oxygen. The encapsulationunit 300 may include: an inorganic film including silicon nitride(SiN_(x)), silicon oxide (SiO_(x)), indium tin oxide, indium zinc oxide,or any combination thereof; an organic film including PET, polyethylenenaphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, poly arylate, hexamethyl disiloxane, an acrylic resin (e.g.,polymethyl methacrylate, polyacrylic acid, and/or the like), an epoxyresin (e.g., aliphatic glycidyl ether (AGE) and/or the like), or anycombination thereof; or a combination of the inorganic film and theorganic film.

FIG. 3 is a schematic cross-sectional view of another electronicapparatus 190 according to one or more embodiments.

The electronic apparatus 190 shown in FIG. 3 may be substantiallyidentical to the electronic apparatus shown in FIG. 2 , except that alight-shielding pattern 500 and a functional area 400 are additionallylocated on the encapsulation unit 300. The functional area 400 may be i)a color filter area, ii) a color-conversion area, or iii) a combinationof a color filter area and a color-conversion area. In some embodiments,the light-emitting device shown in FIG. 3 included in the electronicapparatus may be a tandem light-emitting device.

Manufacturing Method

The layers constituting the hole transport region, the emission layer,and the layers constituting the electron transport region may be formedin a set or specific region by utilizing one or more suitable methodssuch as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB)deposition, ink-jet printing, laser printing, and/or laser-inducedthermal imaging.

When the layers constituting the hole transport region, the emissionlayer, and the layers constituting the electron transport region areeach independently formed by vacuum deposition, the vacuum depositionmay be performed at a deposition temperature in a range of about 100° C.to about 500° C. at a vacuum degree in a range of about 10⁻⁸ torr toabout 10⁻³ torr, and at a deposition rate in a range of about 0.01Angstroms per second (Å/sec) to about 100 Å/sec, depending on thematerial to be included in each layer and the structure of each layer tobe formed.

When the layers constituting the hole transport region, the emissionlayer, and the layers constituting the electron transport region areeach independently formed by spin coating, the spin coating may beperformed at a coating rate of about 2,000 revolutions per minute (rpm)to about 5,000 rpm and at a heat treatment temperature of about 80° C.to about 200° C., depending on the material to be included in each layerand the structure of each layer to be formed.

The ink composition for a light-emitting device according to one or moreembodiments may be utilized in a solution process, such as aspin-coating method and/or an inkjet printing method.

General Definitions of Substituents

The term “C₃-C₆₀ carbocyclic group” as utilized herein refers to acyclic group consisting of carbon atoms only and having 3 to 60 carbonatoms as ring-forming atoms. The term “C₁-C₆ heterocyclic group” asutilized herein refers to a cyclic group having 1 to 60 carbon atoms, inaddition to at least one heteroatom, as ring-forming atoms. The C₃-C₆₀carbocyclic group and the C₁-C₆ heterocyclic group may eachindependently be a monocyclic group consisting of one ring or apolycyclic group in which at least two rings are condensed. For example,the number of ring-forming atoms in the C₁-C₆ heterocyclic group may bein a range of 3 to 61.

The term “cyclic group” as utilized herein may include the C₃-C₆₀carbocyclic group and the C₁-C₆ heterocyclic group.

The term “π electron-rich C₃-C₆₀ cyclic group” refers to a cyclic grouphaving 3 to 60 carbon atoms and not including *—N═*′ as a ring-formingmoiety. The term “π electron-deficient nitrogen-containing C₁-C₆₀ cyclicgroup” as utilized herein refers to a heterocyclic group having 1 to 60carbon atoms and *—N═*′ as a ring-forming moiety.

In some embodiments,

-   -   the C₃-C₆₀ carbocyclic group may be i) a T1 group or ii) a group        in which at least two T1 groups are condensed (for example, the        C₃-C₆₀ carbocyclic group may be a cyclopentadiene group, an        adamantane group, a norbornane group, a benzene group, a        pentalene group, a naphthalene group, an azulene group, an        indacene group, an acenaphthylene group, a phenalene group, a        phenanthrene group, an anthracene group, a fluoranthene group, a        triphenylene group, a pyrene group, a chrysene group, a perylene        group, a pentaphene group, a heptalene group, a naphthacene        group, a picene group, a hexacene group, a pentacene group, a        rubicene group, a coronene group, an ovalene group, an indene        group, a fluorene group, a spiro-bifluorene group, a        benzofluorene group, an indenophenanthrene group, and/or an        indenoanthracene group),    -   the C₁-C₆₀ heterocyclic group may be i) a T2 group, ii) a group        in which at least two T2 groups are condensed, or iii) a group        in which at least one T2 group is condensed with at least one T1        group (for example, the C₁-C₆₀ heterocyclic group may be a        pyrrole group, a thiophene group, a furan group, an indole        group, a benzoindole group, a naphthoindole group, an isoindole        group, a benzoisoindole group, a naphthoisoindole group, a        benzosilole group, a benzothiophene group, a benzofuran group, a        carbazole group, a dibenzosilole group, a dibenzothiophene        group, a dibenzofuran group, an indenocarbazole group, an        indolocarbazole group, a benzofurocarbazole group, a        benzothienocarbazole group, a benzosilolocarbazole group, a        benzoindolocarbazole group, a benzocarbazole group, a        benzonaphthofuran group, a benzonapthothiophene group, a        benzonaphthosilole group, a benzofurodibenzofuran group, a        benzofurodibenzothiophene group, a benzothienodibenzothiophene        group, a pyrazole group, an imidazole group, a triazole group,        an oxazole group, an isoxazole group, an oxadiazole group, a        thiazole group, an isothiazole group, a thiadiazole group, a        benzopyrazole group, a benzimidazole group, a benzoxazole group,        a benzoisoxazole group, a benzothiazole group, a        benzoisothiazole group, a pyridine group, a pyrimidine group, a        pyrazine group, a pyridazine group, a triazine group, a        quinoline group, an isoquinoline group, a benzoquinoline group,        a benzoisoquinoline group, a quinoxaline group, a        benzoquinoxaline group, a quinazoline group, a benzoquinazoline        group, a phenanthroline group, a cinnoline group, a phthalazine        group, a naphthyridine group, an imidazopyridine group, an        imidazopyrimidine group, an imidazotriazine group, an        imidazopyrazine group, an imidazopyridazine group, an        azacarbazole group, an azafluorene group, an azadibenzosilole        group, an azadibenzothiophene group, an azadibenzofuran group,        and/or the like),    -   the π electron-rich C₃-C₆₀ cyclic group may be i) a T1        group, ii) a condensed group in which at least two T1 groups are        condensed, iii) a T3 group, iv) a condensed group in which at        least two T3 groups are condensed, or v) a condensed group in        which at least one T3 group is condensed with at least one T1        group (for example, the π electron-rich C₃-C₆₀ cyclic group may        be a C₃-C₆₀ carbocyclic group, a 1H-pyrrole group, a silole        group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, a        thiophene group, a furan group, an indole group, a benzoindole        group, a naphthoindole group, an isoindole group, a        benzoisoindole group, a naphthoisoindole group, a benzosilole        group, a benzothiophene group, a benzofuran group, a carbazole        group, a dibenzosilole group, a dibenzothiophene group, a        dibenzofuran group, an indenocarbazole group, an indolocarbazole        group, a benzofurocarbazole group, a benzothienocarbazole group,        a benzosilolocarbazole group, a benzoindolocarbazole group, a        benzocarbazole group, a benzonaphthofuran group, a        benzonapthothiophene group, a benzonaphthosilole group, a        benzofurodibenzofuran group, a benzofurodibenzothiophene group,        a benzothienodibenzothiophene group, and/or the like), and    -   the π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group        may be i) a T4 group, ii) a group in which at least two T4        groups are condensed, iii) a group in which at least one T4        group is condensed with at least one T1 group, iv) a group in        which at least one T4 group is condensed with at least one T3        group, or v) a group in which at least one T4 group, at least        one T1 group, and at least one T3 group are condensed (for        example, the π electron-deficient nitrogen-containing C₁-C₆₀        cyclic group may be a pyrazole group, an imidazole group, a        triazole group, an oxazole group, an isoxazole group, an        oxadiazole group, a thiazole group, an isothiazole group, a        thiadiazole group, a benzopyrazole group, a benzimidazole group,        a benzoxazole group, a benzoisoxazole group, a benzothiazole        group, a benzoisothiazole group, a pyridine group, a pyrimidine        group, a pyrazine group, a pyridazine group, a triazine group, a        quinoline group, an isoquinoline group, a benzoquinoline group,        a benzoisoquinoline group, a quinoxaline group, a        benzoquinoxaline group, a quinazoline group, a benzoquinazoline        group, a phenanthroline group, a cinnoline group, a phthalazine        group, a naphthyridine group, an imidazopyridine group, an        imidazopyrimidine group, an imidazotriazine group, an        imidazopyrazine group, an imidazopyridazine group, an        azacarbazole group, an azafluorene group, an azadibenzosilole        group, an azadibenzothiophene group, an azadibenzofuran group,        and/or the like),    -   wherein the T1 group may be a cyclopropane group, a cyclobutane        group, a cyclopentane group, a cyclohexane group, a cycloheptane        group, a cyclooctane group, a cyclobutene group, a cyclopentene        group, a cyclopentadiene group, a cyclohexene group, a        cyclohexadiene group, a cycloheptene group, an adamantane group,        a norbornane (or bicyclo[2.2.1]heptane) group, a norbornene        group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane        group, a bicyclo[2.2.2]octane group, and/or a benzene group,    -   the T2 group may be a furan group, a thiophene group, a        1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole        group, a 3H-pyrrole group, an imidazole group, a pyrazole group,        a triazole group, a tetrazole group, an oxazole group, an        isoxazole group, an oxadiazole group, a thiazole group, an        isothiazole group, a thiadiazole group, an azasilole group, an        azaborole group, a pyridine group, a pyrimidine group, a        pyrazine group, a pyridazine group, a triazine group, a        tetrazine group, a pyrrolidine group, an imidazolidine group, a        dihydropyrrole group, a piperidine group, a tetrahydropyridine        group, a dihydropyridine group, a hexahydropyrimidine group, a        tetrahydropyrimidine group, a dihydropyrimidine group, a        piperazine group, a tetrahydropyrazine group, a dihydropyrazine        group, a tetrahydropyridazine group, and/or a dihydropyridazine        group,    -   the T3 group may be a furan group, a thiophene group, a        1H-pyrrole group, a silole group, and/or a borole group, and    -   the T4 group may be a 2H-pyrrole group, a 3H-pyrrole group, an        imidazole group, a pyrazole group, a triazole group, a tetrazole        group, an oxazole group, an isoxazole group, an oxadiazole        group, a thiazole group, an isothiazole group, a thiadiazole        group, an azasilole group, an azaborole group, a pyridine group,        a pyrimidine group, a pyrazine group, a pyridazine group, a        triazine group, and/or a tetrazine group.

The terms “cyclic group”, “C₃-C₆₀ carbocyclic group”, “C₁-C₆heterocyclic group”, “π electron-rich C₃-C₆₀ cyclic group”, or “πelectron-deficient nitrogen-containing C₁-C₆₀ cyclic group” as utilizedherein may each independently refer a monovalent group, or a polyvalentgroup (e.g., a divalent group, a trivalent group, a quadvalent group,and/or the like), or a group condensed with any suitable cyclic group,depending on the structure of the formula to which the term is applied.For example, a “benzene group” may be a benzene ring, a phenyl group, aphenylene group, and/or the like, and this may be understood by one ofordinary skill in the art, depending on the structure of the formulaincluding the “benzene group”.

Examples of the monovalent C₃-C₆₀ carbocyclic group and the monovalentC₁-C₆ heterocyclic group may include a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆ heteroaryl group,a monovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group. Examples of the divalentC₃-C₆₀ carbocyclic group and the divalent C₁-C₆ heterocyclic group mayinclude a C₃-C₁₀ cycloalkylene group, a C₁-C₁₀ heterocycloalkylenegroup, a C₃-C₁₀ cycloalkenylene group, a C₁-C₁₀ heterocycloalkenylenegroup, a C₆-C₆₀ arylene group, a C₁-C₆ heteroarylene group, a divalentnon-aromatic condensed polycyclic group, and a divalent non-aromaticcondensed heteropolycyclic group.

The term “C₁-C₆₀ alkyl group” as utilized herein refers to a linear orbranched aliphatic hydrocarbon monovalent group having 1 to 60 carbonatoms, and examples thereof may include a methyl group, an ethyl group,an n-propyl group, an isopropyl group, an n-butyl group, a sec-butylgroup, an isobutyl group, a tert-butyl group, an n-pentyl group, atert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentylgroup, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, anisohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptylgroup, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, ann-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group,an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonylgroup, an n-decyl group, an isodecyl group, a sec-decyl group, and atert-decyl group. The term “C₁-C₆₀ alkylene group” as utilized hereinrefers to a divalent group having the same structure as the C₁-C₆ alkylgroup.

The term “C₂-C₆₀ alkenyl group” as utilized herein refers to ahydrocarbon group having at least one carbon-carbon double bond in themiddle and/or at the terminus of the C₂-C₆₀ alkyl group. Examplesthereof may include an ethenyl group, a propenyl group, and a butenylgroup. The term “C₂-C₆ alkenylene group” as utilized herein refers to adivalent group having the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as utilized herein refers to amonovalent hydrocarbon group having at least one carbon-carbon triplebond in the middle and/or at the terminus of the C₂-C₆₀ alkyl group.Examples thereof may include an ethynyl group and a propynyl group. Theterm “C₂-C₆ alkynylene group” as utilized herein refers to a divalentgroup having the same structure as the C₂-C₆₀ alkynyl group.

The term “C₁-C₆ alkoxy group” as utilized herein refers to a monovalentgroup represented by —OA₁₀₁ (wherein A₁₀₁ is a C₁-C₁ alkyl group).Examples thereof may include a methoxy group, an ethoxy group, and anisopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as utilized herein refers to amonovalent saturated hydrocarbon monocyclic group including 3 to 10carbon atoms. Examples of the C₃-C₁₀ cycloalkyl group as utilized hereinmay include a cyclopropyl group, a cyclobutyl group, a cyclopentylgroup, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, anadamantanyl group, a norbornanyl (bicyclo[2.2.1]heptyl) group, abicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, or abicyclo[2.2.2]octyl group. The term “C₃-C₁₀ cycloalkylene group” asutilized herein refers to a divalent group having the same structure asthe C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as utilized herein refers to amonovalent cyclic group including at least one heteroatom other thancarbon atoms as a ring-forming atom, and having 1 to 10 carbon atoms.Examples thereof may include a 1,2,3,4-oxatriazolidinyl group, atetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group” as utilized herein refers to adivalent group having the same structure as the C₁-C₁₀ heterocycloalkylgroup.

The term “C₃-C₁₀ cycloalkenyl group” as utilized herein refers to amonovalent cyclic group that has 3 to 10 carbon atoms and at least onecarbon-carbon double bond in its ring, and is not aromatic. Examplesthereof may include a cyclopentenyl group, a cyclohexenyl group, and acycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” as utilizedherein refers to a divalent group having the same structure as theC₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as utilized herein refers toa monovalent cyclic group including at least one heteroatom other thancarbon atoms as a ring-forming atom, 1 to 10 carbon atoms, and at leastone double bond in its ring. Examples of the C₁-C₁₀ heterocycloalkenylgroup may include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group” as utilized herein refers to adivalent group having the same structure as the C₁-C₁₀ heterocycloalkylgroup.

The term “C₆-C₆₀ aryl group” as utilized herein refers to a monovalentgroup having a carbocyclic aromatic system having 6 to 60 carbon atoms.The term “C₆-C₆₀ arylene group” as utilized herein refers to a divalentgroup having the same structure as the C₆-C₆₀ aryl group. Examples ofthe C₆-C₆₀ aryl group may include a phenyl group, a pentalenyl group, anaphthyl group, an azulenyl group, an indacenyl group, an acenaphthylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a perylenyl group, a pentaphenyl group, a heptalenylgroup, a naphthacenyl group, a picenyl group, a hexacenyl group, apentacenyl group, a rubicenyl group, a coronenyl group, and an ovalenylgroup. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene group eachindependently include two or more rings, the respective rings may befused.

The term “C₁-C₆₀ heteroaryl group” as utilized herein refers to amonovalent group having a heterocyclic aromatic system further includingat least one heteroatom other than carbon atoms as a ring-forming atomand 1 to 60 carbon atoms. The term “C₁-C₆ heteroarylene group” asutilized herein refers to a divalent group having the same structure asthe C₁-C₆ heteroarylene group. Examples of the C₁-C₆ heteroaryl groupmay include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, apyridazinyl group, a triazinyl group, a quinolinyl group, abenzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinylgroup, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinylgroup, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinylgroup, a phthalazinyl group, and a naphthyridinyl group. When the C₁-C₆₀heteroaryl group and the C₁-C₆ heteroarylene group each independentlyinclude two or more rings, the respective rings may be fused.

The term “monovalent non-aromatic condensed polycyclic group” asutilized herein refers to a monovalent group that has two or morecondensed rings and only carbon atoms (e.g., 8 to 60 carbon atoms) asring forming atoms, wherein the molecular structure when considered as awhole is non-aromatic. Examples of the monovalent non-aromatic condensedpolycyclic group may include an indenyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenylgroup, and an indenoanthracenyl group. The term “divalent non-aromaticcondensed polycyclic group” as utilized herein refers to a divalentgroup having substantially the same structure as the monovalentnon-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” asutilized herein refers to a monovalent group that has two or morecondensed rings and at least one heteroatom other than carbon atoms(e.g., 1 to 60 carbon atoms), as a ring-forming atom, wherein themolecular structure when considered as a whole is non-aromatic. Examplesof the monovalent non-aromatic condensed heteropolycyclic group mayinclude a pyrrolyl group, a thiophenyl group, a furanyl group, anindolyl group, a benzoindolyl group, a naphthoindolyl group, anisoindolyl group, a benzoisoindolyl group, a naphthoisoindolyl group, abenzosilolyl group, a benzothiophenyl group, a benzofuranyl group, acarbazolyl group, a dibenzosilolyl group, a dibenzothiophenyl group, adibenzofuranyl group, an azacarbazolyl group, an azafluorenyl group, anazadibenzosilolyl group, an azadibenzothiophenyl group, anazadibenzofuranyl group, a pyrazolyl group, an imidazolyl group, atriazolyl group, a tetrazolyl group, an oxazolyl group, an isoxazolylgroup, a thiazolyl group, an isothiazolyl group, an oxadiazolyl group, athiadiazolyl group, a benzopyrazolyl group, a benzimidazolyl group, abenzoxazolyl group, a benzothiazolyl group, a benzooxadiazolyl group, abenzothiadiazolyl group, an imidazopyridinyl group, animidazopyrimidinyl group, an imidazotriazinyl group, an imidazopyrazinylgroup, an imidazopyridazinyl group, an indenocarbazolyl group, anindolocarbazolyl group, a benzofurocarbazolyl group, abenzothienocarbazolyl group, a benzosilolocarbazolyl group, abenzoindolocarbazolyl group, a benzocarbazolyl group, abenzonaphthofuranyl group, a benzonaphthothiophenyl group, abenzonaphthosilolyl group, a benzofurodibenzofuranyl group, abenzofurodibenzothiophenyl group, and a benzothienodibenzothiophenylgroup. The term “divalent non-aromatic condensed heteropolycyclic group”as utilized herein refers to a divalent group having substantially thesame structure as the monovalent non-aromatic condensed heteropolycyclicgroup.

The term “C₆-C₆₀ aryloxy group” as utilized herein refers to amonovalent group represented by —OA₁₀₂ (wherein A₁₀₂ is the C₆-C₆₀ arylgroup). The term “C₆-C₆₀ arylthio group” as utilized herein refers to amonovalent group represented by —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ arylgroup).

The term “C₇-C₆₀ aryl alkyl group” utilized herein refers to -A₁₀₄A₁₀₅(where A₁₀₄ may be a C₁-C₅₄ alkylene group, and A₁₀₅ may be a C₆-C₅₉aryl group), and the term “C₂-C₆₀ heteroaryl alkyl group” utilizedherein refers to -A₁₀₆A₁₀₇ (where A₁₀₆ may be a C₁-C₅₉ alkylene group,and A₁₀₇ may be a C₁-C₅₉ heteroaryl group).

The term “R_(10a)” as utilized herein may be:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitrogroup;

a C₁-C₆ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, ora C₁-C₆ alkoxy group, each unsubstituted or substituted with deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, aC₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, a C₂-C₆₀heteroaryl alkyl group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂),—C(═O) (Q₁₁), —S(═O)₂(Q₁₁), —P(═O) (Q₁₁)(Q₁₂), or any combinationthereof;

a C₃-C₆₀ carbocyclic group, a C₁-C₆ heterocyclic group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, or a C₂-C₆₀heteroaryl alkyl group, each unsubstituted or substituted withdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, a C₁-C₆ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₇-C₆₀ aryl alkyl group, a C₂-C₆₀ heteroaryl alkyl group,—Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁),—S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof; or

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), or —P(═O)(Q₃₁)(Q₃₂).

Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃ and Q₃₁ to Q₃₃ may each independentlybe: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyanogroup; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; aC₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₆₀ carbocyclic groupor a C₁-C₆₀ heterocyclic group, each unsubstituted or substituted withdeuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxygroup, a phenyl group, a biphenyl group, or any combination thereof; aC₇-C₆₀ aryl alkyl group; or a C₂-C₆₀ heteroaryl alkyl group.

The term “heteroatom” as utilized herein refers to any atom other than acarbon atom. Examples of the heteroatom may include O, S, N, P, Si, B,Ge, Se, and any combination thereof.

A third-row transition metal as utilized herein may include hafnium(Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium(Ir), platinum (Pt), and/or gold (Au).

“Ph” utilized herein represents a phenyl group, “Me” utilized hereinrepresents a methyl group, “Et” utilized herein represents an ethylgroup, “ter-Bu” or “Bu^(t)” utilized herein represents a tert-butylgroup, and “OMe” utilized herein represents a methoxy group.

The term “biphenyl group” as utilized herein refers to a phenyl groupsubstituted with a phenyl group. The “biphenyl group” may be asubstituted phenyl group having a C₆-C₆₀ aryl group as a substituent.

The term “terphenyl group” as utilized herein refers to a phenyl groupsubstituted with a biphenyl group. The “terphenyl group” may be “asubstituted phenyl group” having a “C₆-C₆ aryl group substituted with aC₆-C₆₀ aryl group” as a substituent.

The maximum number of carbon atoms in the definitions are illustrativeonly. For example, the maximum number of carbon atoms in the C₁-C₆ alkylgroup of 60 may be an example and also may be applied to the C₁-C₂₀alkyl group. Other cases may also be the same.

The symbols * and *′ as utilized herein, unless defined otherwise, referto a binding site to an adjacent atom in a corresponding formula.

Hereinafter, a light-emitting device and a compound according to one ormore embodiments will be described in more detail with reference toExamples.

EXAMPLES Manufacture of Light-Emitting Device

An ink composition for an emission layer was prepared according to thecomposition shown in Table 1.

TABLE 1 Second Third solvent solvent (boiling point Quantum dot Firstsolvent [65 (° C.)) [2 (10 nm)-blue [100 vol %] vol %] vol %]Comparative ZnSe shell and Phenyl Hexa- — Example 1 II-VI group corecyclohexane decane Comparative ZnS shell and II- Phenyl Hexa- — Example2 VI group core cyclohexane decane Comparative ZnSe shell and PhenylHexa- — Example 3 III-V group core cyclohexane decane Comparative ZnSshell and Phenyl Hexa- — Example 4 III-V group core cyclohexane decaneExample 1 ZnSe shell and Phenyl Hexa- Tributyl II-VI group corecyclohexane decane phosphine (245) Example 2 ZnS shell and II- PhenylHexa- Tributyl VI group core cyclohexane decane phosphine (245) Example3 ZnSe shell and Phenyl Hexa- Tributyl III-V group core cyclohexanedecane phosphine (245) Example 4 ZnS shell and Phenyl Hexa- TributylIII-V group core cyclohexane decane phosphine (245) Example 5 ZnSe shelland Phenyl Hexa- Trihexyl II-VI group core cyclohexane decane amine(265) Example 6 ZnS shell and II- Phenyl Hexa- Trioctyl VI group corecyclohexane decane amine (365)

The viscosities of Comparative Examples and Examples were about 5 cP,and the surface tensions were all about 28 dyne/cm. The vapor pressureof Comparative Examples and Examples were 10⁻³ mmHg to 9×10⁻³ mmHg.

Manufacture of Electronic Apparatus Comparative Example 5

An electronic apparatus was manufactured by forming an emission layer inthe interlayer 130 as shown in FIG. 2 by utilizing the quantum dot inkcomposition of Comparative Example 1 in Table 1 by utilizing (e.g.,deposited via) an inkjet.

Comparative Examples 6 to 8

Electronic apparatuses were manufactured in substantially the samemanner as in Comparative Example 5, except that the quantum dot inkcompositions of Comparative Examples 2 to 4 in Table 1 were utilized toform an emission layer.

Examples 7 to 12

Electronic apparatuses were manufactured in substantially the samemanner as in Comparative Example 5, except that the quantum dot inkcompositions of Examples 1 to 6 in Table 1 were utilized to form anemission layer.

In order to evaluate characteristics of the electronic apparatusesmanufactured in Comparative Examples 5 to 8 and Examples 7 to 12, anefficiency at a current density 10 mA/cm² were measured. The resultsthereof are shown in Table 2.

Efficiency and/or the like were measured utilizing a measurementapparatus C9920-2-12 manufactured by Hamamatsu Photonics.

TABLE 2 Quantum Peak efficiency (%) position (nm) FWHM (nm) Comparative12.4 450 21 Example 5 Comparative 75 446 18 Example 6 Comparative 58 54038 Example 7 Comparative 83 540 38 Example 8 Example 7 51 450 21 Example8 86 446 18 Example 9 74 540 38 Example 10 95 540 38 Example 11 44 45021 Example 12 80 446 18

From the results shown in Table 2, it was found that the quantumefficiency was improved through defect control without changing the peakposition and FWHM.

It is believed, without being bound by any particular theory, that thismay result from a partial residue of the third solvent—e.g., tributylphosphine, trihexyl amine, and/or trioctyl amine, included in the inkcomposition of the Examples—in the quantum dot of the formed emissionlayer, as the partial residue of the third solvent may form a coordinatebond with a defect site, e.g., a chalcogenide component such as ZnSand/or ZnSe, in the quantum dot shell, thereby preventing or reducingthe risk of the defect site serving as an electron trap.

As should be apparent from the foregoing description, a light-emittingdevice manufactured by utilizing the ink composition according to one ormore embodiments may have excellent or suitable efficiency.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments. While one or more embodiments have beendescribed with reference to the drawings, it will be understood by thoseof ordinary skill in the art that one or more suitable changes in formand details may be made therein without departing from the spirit andscope of the present disclosure as defined by the following claims andequivalents thereof.

What is claimed is:
 1. An ink composition for a light-emitting device,the ink composition comprising: quantum dots; and a mixed solvent of afirst solvent, a second solvent, and a third solvent, wherein the firstsolvent is a C₆-C₆₀ aromatic hydrocarbon, the second solvent is a C₁-C₂₀aliphatic hydrocarbon, and the third solvent is a ternary alkylphosphine and/or a ternary alkyl amine.
 2. The ink composition of claim1, wherein a boiling point of the third solvent is in a range from 220°C. to 500° C.
 3. The ink composition of claim 1, wherein the firstsolvent comprises toluene, xylene, ethyl benzene, diethyl benzene,mesitylene, propyl benzene, cyclohexyl benzene, dimethoxy benzene,anisole, ethoxytoluene, phenoxytoluene, isopropylbiphenyl,dimethylanisole, propylanisole, 1-ethyl naphthalene, 2-ethylnaphthalene, 2-ethylbiphenyl, octyl benzene, or any combination thereof.4. The ink composition of claim 1, wherein the second solvent comprisesn-octane, n-nonane, n-decane, n-undecane, n-dodecane, n-tridecane,n-tetradecane, n-pentadecane, n-hexadecane, 2-methylheptane,3-methylheptane, 4-methylheptane, 2,2-dimethylhexane,2,3-dimethylhexane, 2,4-dimethylhexane, 2,5-dimethylhexane,3,3-dimethylhexane, 3-ethylhexane, 2,2,4-trimethylpentane,2-methyloctane, 2-methylnonane, 2-methyldecane, 2-methylundecane,2-methyldodecane, 2-methyltridecane, or any combination thereof.
 5. Theink composition of claim 1, wherein the third solvent comprisestripropylphosphine, tributylphosphine, trihexylphosphine,trioctylphosphine, tripropylamine, tributylamine, trihexylamine,triheptylamine, trioctylamine, or any combination thereof.
 6. The inkcomposition of claim 1, wherein the second solvent is present in a rangeof about 20 percent by volume (vol %) to about 70 vol %, based on 100vol % of the first solvent.
 7. The ink composition of claim 1, whereinthe third solvent is present in a range of about 1 percent by volume(vol %) to about 20 vol %, based on 100 vol % of the first solvent. 8.The ink composition of claim 1, wherein each of the quantum dots has acore-shell structure and comprises: a core comprising a semiconductorcompound; and a shell comprising a metal oxide, a metalloid oxide, anon-metal oxide, a semiconductor compound, or a combination thereof. 9.The ink composition of claim 8, wherein the semiconductor compoundcomprises a group II-VI semiconductor compound, a group III-Vsemiconductor compound, a group III-VI semiconductor compound, a groupI-III-VI semiconductor compound, a group IV-VI semiconductor compound, agroup IV element, a group IV compound, or any combination thereof, andthe metal oxide, the metalloid oxide, and the non-metal oxide eachindependently comprise SiO₂, Al₂O₃, TiO₂, ZnO, MnO, Mn₂O₃, Mn₃O₄, CuO,FeO, Fe₂O₃, Fe₃O₄, CoO, Co₃O₄, NiO, MgAl₂O₄, CoFe₂O₄, NiFe₂O₄, CoMn₂O₄,or any combination thereof.
 10. The ink composition of claim 8, whereinthe semiconductor compound comprises CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe,ZnO, HgS, HgSe, HgTe, MgSe, MgS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe,ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe,CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, CdZnSeS, CdZnSeTe,CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, GaN,GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP,GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP,InNP, InAlP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb,GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP,InAlNAs, InAlNSb, InAlPAs, InAlPSb, InZnP, InGaZnP, InAlZnP, GaS, GaSe,Ga₂Se₃, GaTe, InS, InSe, In₂S₃, In₂Se₃, InTe, InGaS₃, InGaSe₃, AgInS,AgInS₂, CuInS, CuInS₂, CuGaO₂, AgGaO₂, AgAlO₂, SnS, SnSe, SnTe, PbS,PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe,SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, Si, Ge, SiC, SiGe, or anycombination thereof.
 11. The ink composition of claim 8, wherein thesemiconductor compound comprised in the shell comprises CdS, CdSe, CdTe,ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs,InP, InGaP, InSb, AlAs, AlP, AlSb, or any combination thereof.
 12. Theink composition of claim 1, wherein a viscosity at 25° C. of the inkcomposition is in a range of about 2 centipoise (cP) to about 10 cP. 13.The ink composition of claim 1, wherein a surface tension of the inkcomposition is in a range of about 20 dyne/cm to about 40 dyne/cm. 14.The ink composition of claim 1, wherein a vapor pressure of the inkcomposition is less than 10⁻² mmHg.
 15. A light-emitting devicecomprising: a first electrode, a second electrode facing the firstelectrode; an interlayer between the first electrode and the secondelectrode, the interlayer comprising an emission layer, wherein theemission layer is formed with the ink composition of claim
 1. 16. Thelight-emitting device of claim 15, wherein the interlayer furthercomprises: a hole transport region comprising a hole injection layer, ahole transport layer, an emission auxiliary layer, an electron blockinglayer, or any combination thereof, and/or an electron transport regioncomprising a hole blocking layer, an electron transport layer, anelectron injection layer, or any combination thereof.
 17. Thelight-emitting device of claim 15, wherein the emission layer comprisesthe quantum dots, and surfaces of the quantum dots comprise the ternaryalkyl phosphine and/or the ternary alkyl amine.
 18. The light-emittingdevice of claim 17, wherein the surfaces of the quantum dots comprise achalcogenide component, and wherein: the chalcogenide component; and theternary alkyl phosphine and/or the ternary alkyl amine, are bound via acoordinate bond.
 19. The light-emitting device of claim 17, wherein theternary alkyl phosphine and/or the ternary alkyl amine, comprisestripropylphosphine, tributylphosphine, trihexylphosphine,trioctylphosphine, tripropylamine, tributylamine, trihexylamine,triheptylamine, trioctylamine, or any combination thereof.
 20. Anelectronic apparatus comprising the light-emitting device of claim 15.